Ribbon level shift with print velocity selection



.Fune 24, 1969 o. L. GREER ET AL 3,451,520

RIBBON LEVEL SHIFT WITH PRINT VELOCITY SELECTION Filed June 21, 1967 DONALD L. -GREER JEROME B. O'DANIEL KRIKOR YOSMALI ffi Z 5% ATTORNEY.

United States Patent 3,451,520 RIBBON LEVEL SHIFT WITH PRINT VELOCITY SELECTION Donald L. Greer, Jerome B. ODaniel, and Krikor Yosmali, Lexington, Ky., assignors to International Business Machines Corporation, Armonk, N.Y., a corporation of New York Filed June 21, 1967, Ser. No. 647,813 Int. Cl. B41j 33/56, 23/02, 35/10 US. Cl. 197-157 4 Claims ABSTRACT OF THE DISCLOSURE The preferred embodiment contains a camming plate rigidly connected to the print velocity cam follower in a single element typewriter. Two print velocity cams between which the follower is moved have substantially identical surfaces, to thereby produce the same print velocity in the printing function. As the follower moves, it carries the camming plate. The camming plate positions a pivot point in the ribbon vibrator so that in one position the black ribbon vertical half of a typewriter ri'bbon is lifted to the print position and in the other position the red ribbon half is lifted to the print position. The resulting product is a low cost and practical one which includes both the print velocity structures and a red ribbon shift in the limited space available.

' Background Typewriters of the general kind to which this invention pertains are described in United States Patent 2,919,002 to L. E. Palmer, entitled Selection Mechanism for a Single Printing Element Typewriter, assigned to the assignee to which this invention is assigned.

Similarly, print velocity mechanisms utilized in this inventon have been in typewriters which are essentially as described in United States Patent 3,239,049 to W. F. Voit, Jr., entitled Impression Control Mechanism Automatically Selecting One of a Plurality of Cams, assigned to the same assignee to which this invention is assigned. As described in the specific embodiment of Patent 3,239,- 049, the impression control mechanism is used only to select a relatively high impression for relatively large surface area characters, such as the character M, and relatively lower velocity for small surface area characters, such as the period. In other prior art systems, however, a no-print velocity cam is added by which a normal impression cycle occurs, but the actual movement of the typehead is curtailed to the extent that the typehead does not reach the paper and therefore no printing occurs. .The cam used to achieve this is called the no-print cam. The no-print cam has been used in the prior art to obtain spacing from a cycle of operation which is otherwise that of a character printing cycle.

A red-black ribbon shift between upper and lower portions of a typewriter ribbon is illustrated in United States Patent 3,082,854 to F. E. Becker et al., entitled Typewriter Input Checking Mechanism, assigned to the same assignee towhich this invention is assigned. In that mechanism in order to achieve printing on a different vertical part of the ribbon, the pivoting and movement stopping action on the ribbon vibrator mecahnisms are changed. In accordance generally with the more specific aspects of this invention, the pivot locations of the ribbon vibrator mechanisms are also changed, but in a different system. It should be understood, however, that in its broader aspects this invention includes a direct connection from print velocity mechanisms to red ribbon shift mechanisms as shown in that Patent 3,082,854. The structure in that ice Patent 3,082,854 is a structure occupying space to the extent that sufiicient room is simply not left for the print velocity mechanisms of the above mentioned Patent 3,239,- 049 in a machine of the general type manufactured at this time (although space saving changes could remove this space limitation). Therefore, the preferred embodiment herein shown includes a different red ribbon shift system designed to fit within certain available space.

Summary It is an object of this invention to provide a single element typewriter with both print velocity control and ribbon level shift.

It is a further object of this invention to provide a single element typewriter with print velocity control and ribbon level shift which is economical and practical to manufacture, and which in addition does not require basic redesign or the change of production tooling for large amounts of existing parts of a single element typewriter.

In accordance with this invention the print velocity mechanisms are retained very much the same as in the prior machines, except that two of the cams may be conformed to produce the same print velocity. A camming member is linked to the print velocity cam follower. The structures moved by the camming member as it is positioned between the two print velocity cam surfaces are effective to move mechanisms which control ribbon position during printing. In this manner different areas of the ribbon are selected while the print velocity is as selected. The print velocity mechanisms are a part of the machine, and one or more print velocity cams may be used for some operative purpose, such as for no-print, which is not related to ribbon selection.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawing.

FIG. 1 is a perspective view illustrating the preferred embodiment of this invention and some salient features of the environmental structures of the invention.

FIG. 2 is a perspective as seen from the rear of the typewriter which shows ldetails of the invention.

During normal operation single element print head 1 is rotated and tilted in a manner now well known in the prior art and then the raised symbol on head 1 selected by the rotate-tilt action is bodily impacted into platen 3.-

As a part of this general printing cycle, ribbon vibrator or lift mechanism 5 lifts a typewriter ribbon to a selected vertical position between typehead 1 and. platen 3.

The single element typehead 1 and the structures associated with it are moved across the platen 3 one char; acter width at a time as a line is printed. During an impacting movement in a print operation, print cycle shaft 7 makes one complete revolution, and in doing so provides the energy and forces which move rocker platform 9 (to which typehead 1 is attached) forward into platen 3. All of print velocity cams 11, 13, and'lS are carried by a sleeve that is keyed to print cycle shaft 7 and slideable on it so that the earns 11, 13, and 15 are turned with shaft 7. Depending upon the location of print velocity cam follower 17, one of the three earns 11, 13, and 15 are intersected, and that one controls the movement of cam follower 17. The immediately above described structures are in general the same as the known structures in the prior art, except that in accordance with this invention cams 11 and 15 are conformed the same to thereby proformed to provide no-print velocity. This is of value in certain specific uses (which are known before in the prior art) in which a spacing operation otherwise functionally identical to a printing operation is conducted. In a teletypewriter like terminal this can be important because lost time in a printing operation rarely occurs, while in the more usual spacing operation a tooth in a dog clutch may at times be missed, thereby delaying the spacing cycle somewhat. Also, during production of signals which are to be transmitted, overlap of functions or overlap of function and printing is highly undesirable since this could result in the transmission of an unintelligible jumble, Interlocking to prevent such overlap is obtained when spacing is essentially like a printing operation accompanied by no-print velocity selection, since interposers for this purpose are all interlocked by a ballsometer interlock. The more usual structures in the type of typewriter employed are not in any way interlocked against simultaneous spacing and printing operations.

In accordance with this invention a camming member 23 straddles the print velocity cam follower 17. As in the prior system, follower 17 is attached to lower support member 25, but follower 17 is mounted somewhat differently: for bodily longitudinal movement rather than for the pivoted longitudinal movement shown in the mentioned Patent 3,239,049. One end of a control tape 27 (which is a flat, wire-like member) is attached to follower 17 at point 28 (See FIG. 2), and that end of tape 27 extends leftwardly as viewed from the front of the printer. Tape 27 may extend to any available position for control (such as by looping as shown in Patent 3,239,049) but preferably tape 27 extends across the front of the machine on two pulleys 29, 31 in the manner shown. Right-side pulley 29 is stationary and left-side pulley 31 is generally stationary, but pulley 31 moves small amounts as will be detailed below to permit movement of follower 17. The other end of tape 27 is attached at point 33 to support member 25. Support member 25 moves with print head 1 and the structures associated with head 1 as they move horizontally while printing a line. Tape 27 is held without slack under the pulling bias of spring 35, and it will now be apparent that tape 27 remains pulled tight by spring 35 as the head 1 and structures associated with head 1 move across platen 3. Tape 27 is therefore normally always ready upon loosening at pulley 31 to permit movement of follower 17 under the influence of spring 35.

The black part of a typewriter ribbon is usually the top, transverse half. Therefore, when black printing is desired, cam follower 17 is positioned to the left-side of the printer as viewed from the front and as shown in the FIG. 1. Camming member 23 is in the path of follower 17 and therefore is always positioned by the position of follower 17. Cam follower 17 is positioned to the left simply by the fact that pulley 31 is held at its left-most normal position. Cam follower 17 will then cooperate with cam 11, and an impacting force sutficient to yield an average density print will be obtained. During the same print cycle ribbon lift cam 37 on print cycle shaft 7 causes the ribbon vibrator action. Cam 37 is operative to cause movement of ribbon vibrator 5. Cam 37 turns through one cycle during every operation in which the printing of a symbol of character is conducted.

Ribbon vibrator includes ribbon guides 39 positioned by arms 41 and 43. Both the left and right side of arms 41 are rigidly linked through one transverse flange 45 with the corresponding arm. Therefore, the arms 41 and 43 must move as a unit. The arms 41 and 43 with guides 39 make up an assembly by which a typewriter ribbon in guides 39 is always positioned generally horizontal to the print receiving paper as required in the usual system for printing. The arms 41 and 43 are pivoted at the ends near the front of the printer. This generally is the same as shown in the above mentioned Patent 3,082,854, and the vibrator 5 in accordance with this invention is pushed upward in a manner generally similar to that prior teaching.

Ribbon vibrator lift for black printing as above mentioned occurs as follows. Early in the print cycle ribbon lift cam 37, which is in contact with a ledge 47a of slotted control member 47, begins to pivot member 47 upwardly on pivot point 49. Prior to this link 51 has been pulled rearward in the typewriter by biasing spring 53. That moved control pin 55 rearward through the direct connection with link 57, until movement is stopped by manual control pin 59. Since a pivot point is found at 49, the pin 55, which is positioned furthest from pivot point 49 in the assembly, always moves upwardly the greater amount and therefore always controls the amount of movement of the left arm of arms 41. (As mentioned, the vibrator 5 is so linked together that movement of one side of arms 41 moves essentially the entire vibrator as a unit.) In this specific case of black writing selection, pin 55 (which is always situated under the bottom of the left arm of arms 41) contacts the left arm of arms 41 and moves it upwardly a predetermined amount, which is established basically by the position of pin 55. This amount is, of course, predetermined to be correct to position the top, traverse half of a typewriter ribbon in guides 39 in position for being printed from by print head 1.

A red ribbon operation is, of course, selected manually by the machine operator when the machine is being used as a local or ordinary typewriter. This control is simply effected, as is more fully clarified below, by a single manual setting of control pin 59, which setting is detented into position and retained for as long as red printing is desired. Red ribbon selection of this kind for local typing is basically well know. On the other hand, for control by received signals during reception of signals in the manner of a teletypewriter, for red printing, which is assumed to be from the bottom, transverse half of the typewriter ribbon, a different operation occurs. The pulley 31 is allowed to move rightwardly a predetermined amount under the bias of spring 35. Instructions to select red printing will be in the received intelligence, and these may be transposed so as to cause movement of pulley 31 directly or indirectly by actuation of solenoids. Movement of pulley 31 is structured to be in a predetermined amount just right to move print velocity follower 17 under print velocity cam 15. Cam 15 is conformed substantially the same as cam 11, so that an impacting force from it will be obtained sul'fioient to yield an average density print. Camming member 23 is in the path of follower 17 and therefore is moved to the right with follower 17 as follower 17 is moved by spring 35. As shown in both of the figures, camming member 23 contacts rod 61 and pivots that rod counterclockwise, and further moves on so that rod 61 sits on a flat 23a of camming member 23. The counterclockwise pivoting of rod 61 moves link 51 toward the front of the typewriter. Link 51 pulls link 57 also toward the front. Link 57 is connected to control pin 55 and thus, pin 55 is moved a predetermined amount away from pivot point 49.

The printing action and the ribbon vibrator action is generally as described above. In this situation, however, pin 55 is a predetermined amount further from pivot point 49. Therefore, the upward movement of pin 55, which is in direct control of the upward movement of left arm of arms 41, is a greater amount, an amount which is correct to bring the red ink on the bottom half of a ribbon in guides 39 up to the printing position. It is significant that rod 61 is positioned on the flat 23a since otherwise large enough forces would be translated back during ribbon vibration to overcome spring 35 and thereby disorganize the system.

A significant advantage of this structure is that other print velocity cams, specifically in the preferred embodiment here, the middle cam 13 may be selected. Thus, the

red ribbon shift capability is provided in addition to the print velocity selection capability, both using largely the same space and structures. In this preferred embodiment cam 13 is conformed for no-print. This is significantly advantageous for use in connection with spacing operations as above discussed. It should be clear also, however, that instead of the three print velocity cams, more than three or three differently conformed cams could be provided so that different relative velocities might be selected while still providing red ribbon shift in accordance with this invention. An alternative which occurs is in the provision of four cams, two associated for a high and low velocity for black print, one conformed for no-print, and one conformed for average print density and associated in accordance with this invention with red ribbon selection. In any such system, movement of the cam follower to a position operative to select a certain velocity would be linked to means which would control the transverse ribbon part selected.

In the preferred embodiment shown, the cam 13 is a no-print cam, and the actions of the ribbon vibrator are therefore immaterial when cam 13 is selected. In fact, in the specific structures shown, the top part of a ribbon in guides 39 is selected since camming member 23 has notv moved far enough to pivot rod 61 when follower 17 has only been moved to select cam 13.

It will now be apparent that manual control pin 59 is only a pushing or holding control for pin 55. Pin 59 extends to the front of the typewriter as shown and may be positioned at the front and is held by detent means shown generally as 63. In a receive mode in which full control is to be in response to the signals received, detent means 63 is positioned to hold pin 59 rearward in the typewriters so that pin 55 may be positioned in the two places along the length of arm 41 to thereby select either the' red or the black part of the ribbon.

We claim:

1. A single element printer having a plurality of print velocity cams, a print velocity cam follower relatively moveable into operative relationship with selected different ones of said cams, and means to position different transverse portions of typewriter ribbons for printing, wherein the improvement comprises:

means linked to a part which is moved when said cam follower is moved relative to said print velocity cams, operative to translate the movement associated with the selection of one of said print velocity cams to control positioning which selects one of said transverse portions of a typewritter ribbon for printing. 2. The single element printer as in claim 1 also specifically including a ribbon vibrator and in which said means linked to a part which is moved when said cam follower is moved relative to said print velocity cams, changes the structural relationship associated with said ribbon vibrator so that the extent of movement of said ribbon vibrator during a printing operation is changed. 3. The combination as in claim 2 in which said ribbon vibrator comprises an arm pivoted at one end and linked to at least one ribbon guide at the other end, and in which said arm is pushed by a positionable control member, said control member being positionable to at least two positions on said arm between the point at which said arm is pivoted and the point at which said arm is linked to said guide, said control member being positionable by said means linked to a part which is moved when said cam follower is moved relative to said print velocity cams.

4. The combination as in claim 3 in which said control member is held by a slotted member and said slotted member is moved a predetermined amount to control said ribbon vibrator through said control member, during every normal operation in which said printer prints a symbol.

References Cited UNITED STATES PATENTS 3,082,854 3/1963 Becker et al. 3,204,746 9/ 1965 Wolowitz. 3,237,747 3/1966 Frechette et all. 3,239,049 3/ 1966 Voit.

3,382,963 5/1968 Cralle.

ERNEST T. WRIGHT, JR., Primary Examiner. 

